3 files changed, 35 insertions, 22 deletions

diff --git a/op.c b/op.c
index e9ce52f..6273541 100644
--- a/op.c
+++ b/op.c
@@ -19,7 +19,7 @@ op_flip_vert(struct ida_image *src, struct ida_rect *rect,
     char *scanline;
 
     scanline = ida_image_scanline(src, src->i.height - line - 1);
-    memcpy(dst,scanline,src->i.width*3);
+    memcpy(dst, scanline, ida_image_stride(src));
 }
 
 static void
@@ -27,15 +27,15 @@ op_flip_horz(struct ida_image *src, struct ida_rect *rect,
 	     unsigned char *dst, int line, void *data)
 {
     char *scanline;
-    unsigned int i;
+    unsigned int i, bpp;
 
-    scanline = ida_image_scanline(src, line+1);
+    bpp = ida_image_bpp(src);
+    scanline = ida_image_scanline(src, line);
+    scanline += src->i.width * bpp;
     for (i = 0; i < src->i.width; i++) {
-	scanline -= 3;
-	dst[0] = scanline[0];
-	dst[1] = scanline[1];
-	dst[2] = scanline[2];
-	dst += 3;
+	scanline -= bpp;
+        memcpy(dst, scanline, bpp);
+	dst += bpp;
     }
 }
 
@@ -55,15 +55,14 @@ op_rotate_cw(struct ida_image *src, struct ida_rect *rect,
 	     unsigned char *dst, int line, void *data)
 {
     char *pix;
-    unsigned int i;
+    unsigned int i, bpp;
 
-    pix = ida_image_scanline(src, src->i.height) + line * 3;
+    bpp = ida_image_bpp(src);
+    pix = ida_image_scanline(src, src->i.height) + line * bpp;
     for (i = 0; i < src->i.height; i++) {
-	pix -= src->i.width * 3;
-	dst[0] = pix[0];
-	dst[1] = pix[1];
-	dst[2] = pix[2];
-	dst += 3;
+	pix -= ida_image_stride(src);
+        memcpy(dst, pix, bpp);
+	dst += bpp;
     }
 }
 
@@ -72,15 +71,14 @@ op_rotate_ccw(struct ida_image *src, struct ida_rect *rect,
 	      unsigned char *dst, int line, void *data)
 {
     char *pix;
-    unsigned int i;
+    unsigned int i, bpp;
 
-    pix = ida_image_scanline(src, 0) + (src->i.width-line-1) * 3;
+    bpp = ida_image_bpp(src);
+    pix = ida_image_scanline(src, 0) + (src->i.width-line-1) * bpp;
     for (i = 0; i < src->i.height; i++) {
-	dst[0] = pix[0];
-	dst[1] = pix[1];
-	dst[2] = pix[2];
-	pix += src->i.width * 3;
-	dst += 3;
+        memcpy(dst, pix, bpp);
+	pix += ida_image_stride(src);
+	dst += bpp;
     }
 }
 
diff --git a/readers.c b/readers.c
index b7da842..4fd09fc 100644
--- a/readers.c
+++ b/readers.c
@@ -144,6 +144,19 @@ uint8_t *ida_image_scanline(struct ida_image *img, int y)
     return scanline;
 }
 
+uint32_t ida_image_stride(struct ida_image *img)
+{
+    return pixman_image_get_stride(img->p);
+}
+
+uint32_t ida_image_bpp(struct ida_image *img)
+{
+    uint32_t bits = PIXMAN_FORMAT_BPP(pixman_image_get_format(img->p));
+    uint32_t bytes = bits / 8;
+    assert(bytes * 8 == bits);
+    return bytes;
+}
+
 void ida_image_free(struct ida_image *img)
 {
     assert(img->p != NULL);
diff --git a/readers.h b/readers.h
index 1ad0e94..171ac76 100644
--- a/readers.h
+++ b/readers.h
@@ -89,6 +89,8 @@ int load_free_extras(struct ida_image_info *info);
 
 void ida_image_alloc(struct ida_image *img);
 uint8_t *ida_image_scanline(struct ida_image *img, int y);
+uint32_t ida_image_stride(struct ida_image *img);
+uint32_t ida_image_bpp(struct ida_image *img);
 void ida_image_free(struct ida_image *img);
 
 /* ----------------------------------------------------------------------- */